This invention relates to a fluidic device which utilizes a liquid jet in gaseous surroundings, herein referred to as a free jet.
Conventional fluidic devices generally utilize a submerged jet, whereby the jet fluid is identical to the fluid surrounding the jet stream. The submerged jet entrains fluid from the surroundings as it passes from the emitter nozzle to one or more receiver passageways, thus reducing the energy recovered in the receiver passageways. Fluidic devices of this kind require a substantial pressure head of fluid and are inherently of very low efficiency. When the jet stream is turbulent, a further performance limitation associated with the high turbulent noise levels in the received flows is noted.
A free jet, for example, a liquid jet operating in air, has the potential to eliminate many of the disadvantages of the submerged jet. However, to date, the potential of the free jet has not been realized because of the tendency of the jet to break up or distort when a control jet interacts with it.
In processes involving liquids, it would be advantageous to be able to use the process fluid itself to perform the control function in order to avoid mechanical - fluidic interfacing, as is presently required.